Banca de DEFESA: LUANA ARAÚJO OLIVEIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : LUANA ARAÚJO OLIVEIRA
DATA : 08/02/2021
HORA: 08:30
LOCAL: Instituto de Química - webconferência
TÍTULO:

DETERMINATION OF TALLIUM IN WATER SAMPLES BY HIGH RESOLUTION ATOMIC ABSORPTION SPECTROMETRY WITH CONTINUOUS SOURCE IN GRAPHITE OVEN USING DIRECT SAMPLING OF SOLIDS AFTER PRE-CONCENTRATION ON CHROMATOGRAPHIC FILTER PAPER

PALAVRAS-CHAVES:

Thallium, Chromatographic paper, Direct analysis of solid sample, High-resolution continuum source atomic absorption spectrometry.

PÁGINAS: 80
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Analítica
ESPECIALIDADE: Métodos Óticos de Análise
RESUMO:

Due to the high degree of thallium toxicity and possible contamination of the environment due to the natural presence or by anthropic action in this paper, a simple and fast method for the separation and pre-concentration of thallium in water samples using paper is proposed. chromatographic filter as a solid support with subsequent determination by using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sample analysis(SS HR-CS GF AAS). The chromatographic filter paper disk and EDTA solution were used as the solid phase and masking agent respectively. An investigation of the variables that influence the pre-concentration, such as the pH of the sample, stirring time, sample volume, effect of other species, type and concentration of the masking reagent, was carried out. After optimizing these variables, the analytical method developed showed a preconcentration factor of 57, an precision of 9.4% (thallium solution 10 μg L -1), a limit of detection of  0.0169 µg L-1 and a limit of quantification of 0.0563 µg L-1. Addition and recovery tests were performed and the results varied from 91% to 110%.The accuracy of the method was assessed by analyzing the certified reference material of TDMA 52.4 fortified water and by analyzing water samples using a comparative method that employed an inductively coupled plasma mass spectrometer (ICP-MS). The procedure was applied for the determination of thallium in water samples collected in the city of Barreiras, Bahia, Brazil. The thallium concentrations present in the analyzed samples ranged between 0.0814 and 0.802 μg L-1. The method proved to be simple, fast, efficient and easy to perform for the determination of thallium by SS HR-CS GF AAS.

MEMBROS DA BANCA:
Presidente - 1649202 - LEONARDO SENA GOMES TEIXEIRA
Interno - 286034 - ANA MARIA PINTO DOS SANTOS
Interno - 2422743 - GISELE ANDRE BAPTISTA CANUTO
Interno - 670.936.635-91 - VALFREDO AZEVEDO LEMOS - UFBA
Externo ao Programa - 3897782 - ICARO THIAGO ANDRADE MOREIRA
Externo à Instituição - JORGE LUIS OLIVEIRA SANTOS - UFOB
Externo à Instituição - JORGE SANTOS DE ALMEIDA - UFBA
Externo à Instituição - GEOVANI CARDOSO BRANDÃO - UNEB
Externo à Instituição - ERIK GALVÃO PARANHOS DA SILVA - UESC-BA